Work Required to Empty a Hemispherical Tank

In summary, the conversation was about finding the work required to empty a hemispherical tank through an outlet at the top. The formula for the work was incorrectly given as \int_0^R (p)(g)(\pi)(R^{2})(R - x)dx, which is actually the formula for a cylinder. The correct formula for a hemispherical tank with x measured from the top is \int_0^R (p)(g)(\pi)(R^{2})(R - x)dx with the area-of-slice being π(1 - x²).
  • #1
Precursor
222
0
Homework Statement
Find the work required to empty a tank in the shape of a hemisphere of radius [tex]R[/tex] meters through an outlet at the top of the tank. The density of water is [tex]p kg/m^{3}[/tex]; the acceleration of a free falling body is [tex]g[/tex]. (Ignore the length of the outlet at the top.)


The attempt at a solution

[tex]w = \int_a^b (density)(gravity)(Area-of-slice)(distance)dx
[/tex]

[tex]w = \int_0^R (p)(g)(\pi)(R^{2})(R - x)dx
[/tex]

Is this correct/complete?
 
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  • #2
Hi Precursor! :smile:

(have a pi: π and a rho: ρ and an integral: ∫ and try using the X2 tag just above the Reply box :wink:)
Precursor said:
Find the work required to empty a tank in the shape of a hemisphere of radius [tex]R[/tex] meters through an outlet at the top of the tank. The density of water is [tex]p kg/m^{3}[/tex]; the acceleration of a free falling body is [tex]g[/tex]. (Ignore the length of the outlet at the top.)

[tex]w = \int_0^R (p)(g)(\pi)(R^{2})(R - x)dx
[/tex]

Is this correct/complete?

No, that's the correct formulal for a cylinder (Area-of-slice = πr2).

Try again! :smile:
 
  • #3
So is the area of the slice actually π(1 - x²)?
 
  • #4
Precursor said:
So is the area of the slice actually π(1 - x²)?

Nooo (btw, it might be easier if you measured x from the top instead of from the bottom :wink:)
 
  • #5
Is it π√(R² - x²)?
 
  • #6
Precursor said:
Is it π√(R² - x²)?

With x is measured from the top, yes :smile: except …

lose the square-root! :wink:
(and I'm going to bed :zzz: g'night!)​
 

FAQ: Work Required to Empty a Hemispherical Tank

What is "Work Required to Empty a Hemispherical Tank"?

The "Work Required to Empty a Hemispherical Tank" is a scientific concept that refers to the amount of energy needed to completely drain a tank in the shape of a half sphere, with a known volume and initial water level.

Why is it important to calculate the work required to empty a hemispherical tank?

Knowing the work required to empty a hemispherical tank can help in designing and optimizing systems that involve the use of tanks, such as water treatment plants, chemical reactors, and storage facilities. It can also be used to determine the efficiency of pumps and other devices used to drain the tank.

What factors affect the work required to empty a hemispherical tank?

The work required to empty a hemispherical tank is affected by the volume of the tank, the initial water level, the acceleration due to gravity, and the properties of the fluid being drained, such as density and viscosity.

How is the work required to empty a hemispherical tank calculated?

The work required can be calculated using the formula W = mgh, where W is the work in joules, m is the mass of the fluid being drained in kilograms, g is the acceleration due to gravity in meters per second squared, and h is the height of the water column in meters. For a hemispherical tank, the height (h) can be calculated using the formula h = (2V)/(πr2), where V is the volume of the tank and r is the radius of the tank.

What are some real-world applications of calculating the work required to empty a hemispherical tank?

Some real-world applications include determining the energy needed to empty a water tower, designing efficient drainage systems for swimming pools, and optimizing the operation of industrial tanks used for storage or processing. It can also be used in the design of amusement park rides that involve the use of water tanks, such as log flumes and water slides.

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